Press.



C. REHBEIN.

PRESS. APPLICATION FILED AUG.23, 19x5.

v Patented Apr. 25

3 SHEETSSHEET I.

C. REHBEIN.

I RESS.

. APPLICAT LED Aue.23. 1915.

Patented Apr. 25,

3 SHEETS-SHEE III: I- I? m ii a Z A 2 a c. REHB EIN.

PRESS. V APPLICATION FILED AUG-23' I915- Patented Apr. 25, 1916.

3 SHEETS-SHEET 3.

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CONRAD REHBEIN, 0F DETROIT, MICHIGAN, ASSIGNOR TO THE HAYES MANUFAC- TUBING COMPANY, OFDETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

PRESS.

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Specification of Letters Patent.

Application filed August 23, 1915. Serial no. 46,872.

To all whom it may concern:

Be it known that I, CONRAD REHBEIN, a citizen of the United States, residing. at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Tmprovement in Presses, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to apparatus for forming sheet metal parts such as automobile fenders, automobile seat backs and other sheet metal portions which require a special configuration. The actual forming is done by dies into which the metal is forced or drawn by water under pressure.

The object of the invention is the provision of means to prevent separation of dies under the heavy pressure of water after they have been closed. It is found in actual practice that it is advantageous to allow the dies to withdraw a small fraction of an inch after they have been pressed together. This arrangement results in a gripping of the edges of the metal which is not so positiveas where the dies are held together under immense pressure; consequently although the sheet of metal is gripped sufliciently to allow the proper drawing of the metal into the concavity of, the forming die, the metal is not gripped so tightly that it precludes vation of a hydraulic press embodying my in-. '40

all slippage and consequently the sheets of metal are not so frequently torn as where the grip is wholly positive.

In the drawings,Figure 1 is a side elevention. Fig. 2 is a verticalcross section of the same taken on the line AA of Fig. 1. Fig. 3 is a portion of a vertical cross section showing the dies open and one of the cylinders which operates one-of the sliding blocks. Fig. -'i is a top or plan view of one of said hydraulic cylinders and one of the blocks together with a. portion of the bed upon which it slides.

a designates the guide post or upright of which there are usually four. Upon these slide the sleeves 7) of the ram 0. The center of the ram at the bottom is formed into apiston 61 which reciprocates in the cylinder 6. The piston is driven up by water under pressure which is forced into the bottom of the cylinder through the intake pipe f. The

upper face of the ram is provided with a plurality of cross grooves g of inverted 'll'-' shape in cross section. These allow the bolt heads of the bolts h secured to the lower die to be slid into the ram and hence when the nuts on the top of the bolts are tightened,

the lower die is securely fastened to the ram at"'tl 1e desired position on-the ram. The upper die 2' which is here shown as the female die is similarly secured to the bolster j of the press. shown are dies for the pressing of crown fenders for automobiles. The male die is the lower, the female die the upper one. The female die is provided with a concavity k which is similar to the shape of the crown desired in the finished fender. Air vent holes .2 are provided to prevent the air being trapped in the female die. The male die is distribution of the water underneath the sheet of metal out of which the fender is to be formed. Water is admitted to this shallow concavity through the passage-way Z of the male die. This passage-way is furnished with water under pressure through the feedwater pipe m. This feed-water pipe is made up of two portions which come together in a telescoping joint within the sleeve n to ac commodate the feed-water pipe to the travel of the ram. This is no part of the present invention'and hence is not illustrated in detail. It will be noted that the male diev is provided with a pair of rubber insert strips 0. These form gaskets which grip the sheet of metal and form a liquid tight joint between the metal and the die so as to prevent the escape of the water.

Whenin operation a sheet of metal coated with a drawing compound is inserted between the male and female dies. Water under heavy pressure is turned into the cylinder e and this gradually forces the ram, -with the male die against the female die.

The dies as here Patented Apr. 25, rare.

- cylinder may be allowed to escape through to readily slide in under the ram and then 25. ton of'the ram. In this sliding block arram may then gradually drop down opening tightly engage with the same. It is advisable to provide a similar cylinder, piston, and sliding block on the opposite side of the ram. This is shown in Fig. 2. The purpose of these sliding blocks is to securely hold the dies together and resist the enormous pressure of the water forced in between the dies. This pressure usually mounts up to 1500# per square inch before the water is turned off and the dies are opened. If it were not for these sliding blocks or some equivalent arrangement the pressure betweenthe dies would have to be resisted by suitable and greater pressure under the pisrangement, as soon as the block is brought under the ram, the pressure under the piston of the ram can be relieved.

When it is desired to open the dies' the water under pressure is turned into the passage-way s to allow the water to flow into the end of the cylinder p near the press and the hand valve 3/ is turned to allow the water to drain out of the farther exhaust passage :2. This causes the piston to travel toward the farther end of the cylinder and carries the block 7- out from under the ram. The

the' dies and formed out of clings.

One very important advantage that I have found to flow from relieving the pressure upon the ram is the lessening of the number of pieces of work that are torn. This is attributed to the fact that with the blocks and ram properly calculated so as not to force the dies together in too positive a fashion, the gripping of the sheet metal is not quite so positive as would otherwise be the case were it necessary to utilize a greater water pressure on the ram than the pressure between the dies. Hence a very small slippage is possible between the gaskets and the sheet of metal, which lessens the possibility of tearing the sheet metal the metal which has been into the fender can then be pried the female die to which it usually where the sheet metal is subjected to unusual strains during the drawing operation.

For the purpose of illustration I have shown valves controlled by hand wheels for each hydraulic cylinder that operates a sliding block, but it will be readily understood that the valves which control these two cylinders p and the valves which control the water which lifts the ram, and the water utilizing water under pressure, the combination of a pair of dies formed suitably to receive water under pressure, a ram for carrying the movable die, means for moving the ram and one or more slidable blocks adapted to be slid under the ram when the dies have been brought together by the travel of the ram.

- 2. In a press for forming sheet metal by utilizing water under pressure, the combination of a pair of dies suitably formed for receiving Water under pressure between the dies, a ram provided with a piston and intended for carrying the movable die, a fiuidoperated cylinder in which the piston of the ram reciprocates and means for the ram to hold the dies from separation after being brought together so that the fluid pressure under the ram can be relieved.

3. In a press for forming sheet metal by utilizing water under pressure, the combination of a pair of dies suitably formed for receiving water under pressure between the same, a ram for carrying the movable die, one or more blocks for sliding under the ram to hold the dies togetheragainst the separation urged by the water pressure therebetween, one or more fluid-operated cylinders and pistons for controlling the movement of the block or blocks.

4. In a press for forming sheet metal by utilizing water under pressure, the combination of a pair of dies suitably formed for receiving water pressure therebetween, a ram for carrying the movable die, said ram bar.- ing one or morebeveled faces on its under surface, means for causing the ram to travel, and one or more beveled-face blocks for sliding under the ram into engagement with the beveled face or faces of said ram.

In testimo y whereof, I sign this specification.

CONRAD REHBEIN.

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